Thin film piezoelectric element, method of manufacturing the same, and actuator

A thin film piezoelectric element comprising a structure having an electrode leading area, and an insulating layer covering an outer periphery of said structure along a thickness of said structure, wherein:

• said structure comprises
• a first main electrode layer and a first opposite electrode layer,
• a first piezoelectric thin film disposed between said first main electrode layer and said first opposite electrode layer,
• a second main electrode layer and a second opposite electrode layer, and
• a second piezoelectric thin film disposed between said second main electrode layer and said second opposite electrode layer;
• said first piezoelectric thin film and said second piezoelectric thin film being coupled so that said first opposite electrode layer and said second opposite electrode layer are opposed to each other and are physically and electrically connected to each other;
• said first main electrode layer in said electrode leading area includes a first main electrode layer projection partially extending from said first piezoelectric thin film;
• a first connection wiring for connecting said first main electrode layer projection and said second main electrode layer is disposed via a first opening that is formed through said insulating layer on said first main electrode layer projection;
• and
• said second main electrode layer, said second piezoelectric thin film and said second opposite electrode layer in said electrode leading area are formed narrower than said first opposite electrode layer so as to provide a region in which said insulating layer is provided on said first opposite electrode layer;
• and
• a second connection wiring for establishing an electrical connection to said first opposite electrode layer is disposed via a second opening that is formed through said insulating layer on said first opposite electrode layer in the region.

A thin film piezoelectric element comprising:

• a pair of element parts disposed in a plane with a predetermined space held therebetween;
• a piezoelectric function area operating as a piezoelectric body of the pair of said element parts having mirror images symmetrical with respect to a centerline of the predetermined space;
• a joint for coupling said element parts in a part of the predetermined space using at least one kind of material comprising said element parts;
• wherein:
• each of the pair of said element parts comprises a structure having an electrode leading area, and an insulating layer covering an outer periphery of said structure along a thickness of said structure, said structure of each of the pair of said element parts comprising
• a first main electrode layer and a first opposite electrode layer,
• a first piezoelectric thin film disposed between said first main electrode layer and said first opposite electrode layer,
• a second main electrode layer and a second opposite electrode layer, and
• a second piezoelectric thin film disposed between said second main electrode layer and said second opposite electrode layer;
• said first main electrode layer in said electrode leading area includes a first main electrode layer projection partially extending from said first piezoelectric thin film;
• said second main electrode layer, said second piezoelectric thin film, and said second opposite electrode layer in said electrode leading area are formed narrower than said first opposite electrode layer so as to provide a region in which said insulating layer is provided on said first opposite electrode layer;
• at least one of a first opening formed through said insulating layer on said first main electrode layer projection and a second opening formed through said insulating layer on said first opposite electrode layer in the region;
• and
• a connection wiring connecting to one of said first opposite electrode layer and said first main electrode layer and leading to a surface layer via one of said first opening and said second opening.